Merge remote-tracking branch 'remotes/dgibson/tags/submodule-update-20170303' into staging

submodule updates (SLOF & dtc) 2017-03-03

This set of patches updates the SLOF and dtc submodules for qemu-2.9.

The SLOF update could have gone in my ppc pull request earlier today,
but I forgot it.  It should be safe to apply in either order with that
set though.

The dtc (and libfdt) update brings us up to dtc 1.4.3 which includes
some things that will be useful in future.

# gpg: Signature made Fri 03 Mar 2017 06:29:31 GMT
# gpg:                using RSA key 0x6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/submodule-update-20170303:
  Update dtc submodule to v1.4.3
  pseries: Update SLOF firmware image

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>